technetium-tc-99m-tetrofosmin and Hyperparathyroidism--Primary

Considered rare disease in the past, primary hyperparathyroidism (PHPT) has dramatically increased in incidence over the past thirty years with the introduction of routine calcium measurements; it is now approximately 42 per 100 000 persons. By far, the most common lesion found in patients with PHPT is the solitary parathyroid adenoma, occurring in 85%-90% of patients, while in the rest 10%- 15% primary hyperplasia of the parathyroid glands is present. Currently, the most widely used surgical approach is minimally invasive parathyroidectomy which is associated with less post-surgery complications and shorter operation time. To be successful this procedure needs to rely on a precise preoperative localization of the abnormal parathyroid glands, hence preoperative parathyroid imaging gained so large importance. The rationale for locating abnormal parathyroid tissue prior to surgery is that the glands can be notoriously unpredictable in their location. There is a general consensus that the best imaging procedure identifying abnormal parathyroid glands is the preoperative scintigraphy with 99mTc-sestamibi or 99mTc-tetrofosmin. It is characterized with high sensitivity and specificity exceeding those of ultrasound, CT or MRI. Combining scintigraphy with the other imaging techniques increases the precision for topic localization.

Topics: Humans; Hyperparathyroidism, Primary; Hyperparathyroidism, Secondary; Nuclear Medicine; Organophosphorus Compounds; Organotechnetium Compounds; Parathyroid Glands; Positron Emission Tomography Computed Tomography; Technetium Tc 99m Sestamibi

Despite recommendations for 99mTc-tetrofosmin dual tracer imaging for hyperparathyroidism in current guidelines, no report was published on dual-isotope 99mTc-tetrofosmin and 123I sodium iodide single-photon-emission-computed-tomography (SPECT). We evaluated diagnostic accuracy and the impact of preoperative SPECT on the surgical procedures and disease outcomes.. Analysis of 70 consecutive patients with primary hyperparathyroidism and 20 consecutive patients with tertiary hyperparathyroidism. Imaging findings were correlated with surgical results. Concomitant thyroid disease, pre- and postoperative laboratory measurements, histopathological results, type and duration of surgery were assessed.. In primary hyperparathyroidism, SPECT had a sensitivity of 80% and a positive predictive value of 93% in patient-based analysis. Specificity was 99% in lesion-based analysis. Patients with positive SPECT elicit higher levels of parathyroid hormone and higher weight of resected parathyroids than SPECT-negative patients. Duration of parathyroid surgery was on average, approximately 40 minutes shorter in SPECT-positive than in SPECT-negative patients (89 ± 46 vs. 129 ± 41 minutes, p = 0.006); 86% of SPECT-positive and 50% of SPECT-negative patients had minimal invasive surgery (p = 0.021). SPECT had lower sensitivity (60%) in patients with tertiary hyperparathyroidism; however, 90% of these patients had multiple lesions and all of these patients had bilateral lesions.. Dual-isotope SPECT with 99mTc-tetrofosmin and 123I sodium iodide has a high diagnostic value in patients with primary hyperparathyroidism and allows for saving of operation time. Higher levels of parathyroid hormone and higher glandular weight facilitated detection of parathyroid lesion. Diagnostic accuracy of preoperative imaging was lower in patients with tertiary hyperparathyroidism.

Topics: Adult; Aged; Female; Humans; Hyperparathyroidism; Hyperparathyroidism, Primary; Iodine Radioisotopes; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Outcome Assessment, Health Care; Parathyroid Glands; Preoperative Period; Reproducibility of Results; Sensitivity and Specificity; Sodium Iodide; Tomography, Emission-Computed, Single-Photon

The impact of preoperative scintigraphy on the management of patients with primary hyperparathyroidism has been largely documented for more than two decades. More recently, preoperative scintigraphy has also been used to select patients for intraoperative detection of hyperfunctioning parathyroid glands thanks to a gamma-probe. This procedure is now widely used, with MIBI as the main radiopharmaceutical for both preoperative scintigraphy and intraoperative detection. However MIBI was not available in Slovakia until very recently and tetrofosmin (TF), the alternative 99mTc labelled radiopharmaceutical for myocardial imaging has some advantages over MIBI and a close biological behaviour. Thus we have been using TF also for parathyroid preoperative scintigraphy and for intraoperative detection, a systematic indication which has never been reported by others. This article aims to demonstrate the feasibility and to present our protocol for TF parathyroid imaging and intraoperative detection, closely associating surgeons, nuclear medicine specialists, pathologists and also biologists as intraoperative assay of intact PTH is necessary. The results of literature are subsequently reported and discussed (Tab. 2, Fig. 4, Ref. 35). Full Text in free PDF www.bmj.sk.

Topics: Humans; Hyperparathyroidism, Primary; Intraoperative Period; Minimally Invasive Surgical Procedures; Organophosphorus Compounds; Organotechnetium Compounds; Parathyroid Glands; Parathyroid Neoplasms; Parathyroidectomy; Radionuclide Imaging; Radiopharmaceuticals; Technetium Tc 99m Sestamibi